Dry cleaning apparatus with solvent recovery



J. w. JAcoss 3,221,525

DRY CLEANING APPARATUS WITH SOLVENT RECOVERY Dec. 7, 1965 Filed Feb. 28, 1963 INVENTOR Jam es W Jacobs United States Patent O 3,221,525 DRY CLEANING APPARATUS WITH SLVENT RECUVERY .lames W. Jacobs, Dayton, h10, assigner to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Feb. 28, 1963, Ser. No. 261,641 3 Claims. (Cl. 68-18) This invention relates to domestic dry cleaner systems and more particularly to a domestic dry cleaner system having a combination cleaner-dryer and a pressurized vapor recovery system.

Domestic dry cleaner systems preferably include a provision for effecting the recovery of heated vaporized solvent therefrom following the cleaning operation. For safety, a non-toxic type of solvent is preferred. Such a solvent is often highly volatile, for example, it typically may have a boiling point in the range of 110 F. at atmospheric pressures. Such vaporized solvent is typically heated to about 140 F. when it leaves the appliance. Accordingly, in order to recover such heated vaporized solvent in conventional recovery systems operating substantially at atmospheric pressure, it has been necessary to provide condensers having a relatively large cooling capacity in order to reduce the temperature of the vaporized solvent to condense it into a liquid form. Such condenser arrangements are often relatively large and bulky and, therefore, unsuited for a practical domestic appliance arrangement where space is a primary design consideration.

Accordingly, an object of the invention is to provide an improved domestic dry cleaning system including a recovery system capable of recovering vaporized solvent with a minimum of condenser cooling capacity.

A furthe-r object is to effect recovery of vaporized solvent from a cleaning chamber of a domestic dry cleaning system by drawing the solvent therefrom and passing it into heat transfer relationship with la condenser under pressures substantially above atmospheric pressure.

A still further object of the invention is to improve the recovery of vaporized solvent from a cleaning chamber of a domestic dry cleaning system where the chamber is characterized by the fact that it is substantially sealed from atmosphere, by providing means in association therewith for drawing vaporized solvent therefrom to reduce the pressure therein to effect additional vaporization of liquid solvent present therein and to force such vaporized solvent therefrom under pressures substantially above atmospheric pressure into heat exchange relation with a condenser and to maintain the vaporized solvent under such pressures in the vicinity of the condenser.

A still further object of the invention is to effect recovery of vaporized solvent from the cleaning chamber of a domestic dry cleaning system by drawing it therefrom and forcing it under pressure into heat exchange relationship with liquid solvent in a pressurized liquid solvent storage tank.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

The drawing is a schematic, sectional view of a dry cleaning system including the present invention.

The drawing is directed to a domestic dry cleaning system having a combination clothes cleaner and dryer unit operatively associated with a vaporized solvent recovery unit 12 and a liquid solvent storage and circulation system 14.

The combination clothes cleaner and dryer unit 12 has 3,221,525 Patented Dec. 7, 1965 Cice a generally box-like outer casing 16 including generally central bulkhead portions 18, 20 dividing the outer casing 16 into a lower machinery compartment 22 and an upper cleaning and drying compartment 24. More particularly, the upper compartment 24 includes a generally cylindrical container or bulkhead 26 enclosing a spin tub assembly 2S yieldably carried on a flexible hat member 30. A top wall 32 of the outer casing 16 forms a central opening 34 for access inwardly of the outer casing 16 to the spin tub assembly 28, and a hinged door 36 is supported by the top wall 32 for closing the central opening 34 during the operation of the combination unit. The hinged door 36 is representatively illustrated as being hollow and having a door duct 38 formed therein between an opening 49 in the corner wall 42 thereof and an -opening 44 in the bottom wail 46 thereof.

The spin tub assembly 28 includes an outer tub 48 and an inner tub 5t) snugly nested therein that has the side wall thereof encircling an agitator assembly 52 including a hollow cylindrical support member S4 carrying a plurality of rubber di-aphragms 56 on the outside surface at the upper end thereof and a relatively larger diameter diaphragm or energy ring 5S at the bottom end thereof. The upper end of the hollow support member 54 is connected to an upper bellows 60 for communicating the support member with the door duct 38 and the lower end thereof is connected to an imperforate bellows arrangement 62 having one end thereof fastened over a collar 64 formed in a false bottom or partition 66 dividing the inner tub 56 into a lower air passage chamber 67 and an upper clothes agitation chamber 68. The partition 66 has a plurality of perforations 65 in a restricted area thereof for reasons to be discussed. The upper and the lower bellows 69, 62 are of a suitable flexible material allowing vertical movement of the agitator assembly 52 relative to the outer and inner tubs 48, 50.

The agitator assembly 52 is connected t-o an agitate shaft 69 by a spider or cross bar 70 connected to the bottom end of the hollow `support member 54. The agitate shaft 69 also is selectively connected to the inner tu-b 50 through a clutch mechanism 71 for reciprocation relative to the outer tube 4S. Additionally, the outer tub 48 is connected to a spin shaft 72 by a plate 73.

Vertical movement of the agitator assembly 52 and of the inner tub 50 as well as spinning of the inner tub Sti is accomplished by means of an agitating and spin mechanism 76 located within the machinery compartment 22 and carried on a tubular housing 78 suspended from the hat-shaped support member 31B on the bulkhead 29. A twospeed reversible motor 82 is operatively associated to an agitating and spinning mechanism 84 by means of a conventional belt and pulley arrangement 86 for effecting selectively either a rotation of the spin shaft 72 or reciprocation of the agitate shaft 69. This mechanism is more fully disclosed in the patent to Sisson et al. 2,974,542, issued on March 14, 1961, hereby incorporated by reference for a -better understanding of the operation of one agitating and spinning mechanism suitable for use in this invention.

The liquid solvent circulation system 14 for supplying solvent to the spin tub assembly Z8 is representatively shown as including a pump 88 which passes liquid solvent from a storage tank 90 through a lter 92 and thence through a conduit 94 to a nozzle or chute 96 into the inner tub Sil. Solvent passes from the spin tub assembly 28 through outlet ports 97 at the upper end thereof to be collected by the central bulkhead portion 20 from whence it drains out an outlet 98 formed therein through a return conduit 10u communicating back to the liquid solvent storage tank 90. A conventional filter or button trap 102 removes any large particles 0r sludge from the returned liquid solvent and a cooling coil arrangement 103 in the tank 90 cools the liquid solvent therein to a predet-ermined desired temperature.

In operation, the door 36 of the combination cleanerdryer 10 is open and clothing is distributed on the partition 66 in the inner tub 50. Liquid solvent is directed to the spin tub assembly 28 until the inner tub Si) is substantially full. As the inner tub is filled it is depressed by the weight of the liquid solvent and the clutch 71 disengages the inner tub 50 from the agitate shaft 69. Then the motor 82 is energized to drive the mechanism 54 and the pulsator or agitate assembly 52 is reciprocated vertically in the inner tub 50 to produce a conventional clothes cleaning action.

At the conclusion of cleaning, the agitating and spinning mechanism S4 is conditioned for spin and the spin tub assembly 28 is rotated at high speed through the spin shaft 72 to centrifuge liquid solvent from the inner tub 50 and the clothes through the outflow ports 97 in the outer tub 48. The solvent then returns through the drain outlet 98 and return conduit 100 to the liquid solvent storage tank 90.

Following the spin cycle, the operation of the combination cleaner and dryer 1l) enters a drying cycle which includes agitation of the inner tub S caused by the lightening of the tub by the removal of the liquid solvent therefrom to thereby cause the clutch 71 to engage the inner tub t) with the agitate shaft 69.

The above-described combination cleaner and dryer unit is taught more fully in application Serial Number 147,- 844 of lohn A. Taylor et al., led October 26, 1961, now Patent No. 3,091,955, as to both additional operational and structural features, it being understood that the cleaner and dryer unit is representative of one such combination unit suitable for use with the present invention.

One aspect of the present invention is improved recovery of vaporized solvent from the combination unit 12 during the drying cycle thereof. To accomplish such improved recovery a heater 104 is located in a duct 106 having one end communicating with the door duct 38 and the other end thereof open vto atmosphere, and a pump element 108 of the vaporized solvent recovery unit 14 has the inlet 109 thereof communicating interiorly of the bulkhead 26. The heater 104 and pump 108 are both energized during the drying cycle whereby the pressure within the bulkhead 26 is reduced causing a flow of heated air through the duct 106, the door duct 38, the hollow cylindrical support member 54, and thence through the air passage chamber 67, upwardly therefrom through the perforations 65 in the restricted area of the partition 66 and thence outwardly of the spin tub assembly 28 through the upper end thereof into the space enclosed by the bulkhead 26. This circulation of air carries along any vaporized solvent present Within the spin tub assembly 28 and by heating the air by means of the heater 104 liquid solvent in the spin tub assembly 28 is vaporized and drawn therefrom along with the circulated air stream.

The air and vaporized solvent are drawn from the interior of the bulkhead 26 by the pump element 108 and are forced under pressure thereby through a conduit 11@ into a condenser unit 112 representatively illustrated as being cooled by means of a water cooling system including an inlet line 114 and outlet line 116 with the flow of the cooling medium therethrough being controlled by a valve 118 in the inlet line 114. In accordance with the principles of the present invention the pressurized vapor solvent from the pump 108 is maintained under a pressure in the vicinity of the condenser 112 substantially above atmospheric pressure by means of pressure control valves 120, 122 located, respectively, in an air outlet line 124 and a liquid solvent outlet line 126 from a conventional separator arrangement 12S that separates air and condensed solvent from the condenser 112. The air outlet line 124 may communicate back to the interior space of the bulkhead 26 and the liquid solvent outlet line 126 is returned to .theliquid solvent storage tank 91).

The foregoing vaporized solvent recovery unit produces satisfactory solvent recovery without the need for a relatively large cooling capacity condenser, since condensation will occur at elevated temperatures because of pressurization of the vaporized solvent during condensation. Such a system is especially suited for use with domestic cleaner and dryer units, such as that previously discussed, where it is preferred to use a nontoxic solvent, for example, Valclene (essentially a fluorinated hydrocarbon such as Freon 113) made by Du Pont Corporation. Such solvents have boiling points in the range of F. and when they are condensed under atmospheric or near atmospheric pressures the condenser must have relatively great cooling capacity. Such a condenser has dimensions too large for practical domestic installations. By operating the system under pressure, as discussed above, the cooling capacity of the condenser can be reduced suiciently to solve such space problems. When Valclene is used as a solvent, the term substantially above atmospheric pressure, as used above, is intended to indicate pressures in the range of 5-10 p.s.i.g. with it being understood that solvents having even greater volatility might require greater pressurization to obtain desired condensation at elevated vaporized solvent temperatures. Additionally, the invention contemplates suiicient pressurization of heated vaporized solvent to produce condensation without a cooling condenser, though, in the preferred arrangement, some condenser cooling is desired to avoid returning hot liquid solvent to the liquid storage tank 90.

While the embodiments of the present invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. In a dry cleaner system, a spin tub for cleaning articles, an enclosure surrounding said spin tub including a liquid solvent sump region and a vaporized solvent collection region, a liquid solvent circuit including a storage tank, means for draining liquid solvent from said sump region into said storage tank and means for directing liquid solvent from said storage tank into said spin tub, a vaporized solvent circulation system including an inlet in said enclosure communicating with atmosphere and an outlet from said enclosure, uid passage means for serially connecting said spin tub between said inlet and said outlet for circulating air from the bottom thereof to the top thereof, pump means connected to said outlet for drawing air through said spin tub as a single pass from said inlet through said iluid passageway means and said outlet, means for heating said air stream to vaporize solvent in said spin tub, said pump means compressing air and vaporized solvent from said spin tub, a condenser for receiving said compressed vaporized solvent and air mixture from said pump means, means for maintaining said discharged mixture from said pump means under pressure in said condenser, and means for directing air from said condenser back to atmosphere and for returning condensed solvent therefrom back to said liquid storage tank.

2. In a dry cleaner system, the combination of, a cleaning chamber, an enclosure surrounding said cleaning chamber having an inlet and an outlet, iluid passage means for connecting said cleaning chamber in serial fluid flow relationship between said inlet and said outlet, said inlet of said enclosure continually communicating with atmospheric air surrounding said enclosure, pump means connected to said outlet operative to circulate fresh air from exteriorly of said enclosure through said inlet thence through said fluid passage means and said cleaning chamber for sweeping solvent therefrom for passage through said outlet, means for heating air being drawn through said cleaning chamber to vaporize solvent in said-cleaning chamber, a condenser, said pump means discharging said heated air and vaporized solvent into said condenser, means for maintaining said air and vaporized solvent under pressure in said condenser, separator means in fluid communication with said condenser for separating air passing therefrom from condensed solvent, a liquid solvent collecting tank for receiving the condensed solvent, and means for separately directing the separated solvent into said tank and said separated air to atmosphere.

3. In a dry cleaner system, the combination of, a cleaning chamber, an enclosure surrounding said cleaning chamber having an inlet continually communicating with atmosphere and an outlet, fluid passageway means for connecting said cleaning chamber in serial fluid flow relationship between said inlet and said outlet, means for heating air passing through said inlet into said cleaning chamber for vaporizing liquid solvent therein, pump means in communication with said outlet operative to draw air through said inlet into heat transfer relationship with said heating means and to direct the heated air through said oW passageway means and said cleaning chamber to sweep the interior thereof of vaporized solvent and to direct the heated air and vaporized solvent through said outlet, a condenser having an inlet and an outlet, said pump means discharging heated air and vaporized solvent into said condenser inlet, means for maintaining said heated air and vaporized solvent under pressure While in said condenser, separator means for receiving air and condensed solvent from said condenser, an atmospheric liquid solvent storage tank, said separator means including an outlet air line and an outlet liquid solvent line communicating respectively with atmosphere and with said tank, said means for maintaining condenser pressure including a pressure control valve in each of said separator outlet lines.

References Cited by the Examiner UNITED STATES PATENTS 1,697,766 l/1929 Hirst 68-18 2,019,896 1l/l935 Edlich 68-18 2,639,599 5/1953 Wellford 68-18 3,122,908 3/1964 Stanulis et al 68-18 X WALTER A. SCHEEL, Primary Examiner.

WILLIAM I. PRICE, Examiner. 

1. IN A DRY CLEANER SYSTEM, A SPIN TUB FOR CLEANING ARTICLES, AN ENCLOSURE SURROUNDING SAID SPIN TUB INCLUDING A LIQUID SOLVENT SUMP REGION AND A VAPORIZED SOLVENT COLLECTION REGION, A LIQUID SOLVENT CIRCUIT INCLUDING A STORAGE TANK, MEANS FOR DRAINING LIQUID SOLVENT FROM SAID SUMP REGION INTO SAID STORAGE TANK AND MEANS FOR DIRECTING LIQUID SOLVENT FROM SAID STORAGE TANK INTO SAID SPIN TUB, A VAPORIZED SOLVENT CIRCULATION SYSTEM INCLUDING AN INLET IN SAID ENCLOSURE COMMUNICATING WITH ATMOSPHERE AND AN OUTLET FROM SAID ENCLOSURE, FLUID PASSAGE MEANS FOR SERIALLY CONNECTING SAID SPIN TUB BETWEEN SAID INLET AND SAID OUTLET FOR CIRCULATING AIR FROM THE BOTTOM THEREOF TO THE TOP THEREOF, PUMP MEANS CONNECTED TO SAID OUTLET FOR DRAWING AIR THROUGH SAID SPIN TUB AS A SINGLE PASS FROM SAID INLET THROUGH SAID FLUID PASSAGEWAY MEANS AND SAID OUTLET, MEANS FOR HEATING SAID AIR STREAM TO VAPORIZE SOLVENT IN SAID SPIN TUB, SAID PUMP MEANS COMPRESSING AIR AND VAPORIZED SOLVENT FROM SAID SPIN TUB, A CONDENSER FOR RECEIVING SAID 